Viscosity Measurements of Fe-Si-BCu-Nb-C Metallic Glass Melts by an Oscillating Crucible Method

Dependence of the dynamic viscosity of new type of Fe-based
amorphous alloy (Fe_68.5Si_13.5B₉Cu₁Nb₃C₅) melt on temperature is investigated by using a torsional oscillation viscometer. The temperature dependence of the viscosity can be fitted by the Arrhenius relation and Fulcher expression as lnη = 0.082+ 1463.48/T and lnη = 6.75 x 10^-5+954.71/(T-608.36), where η is the viscosity in units of cP and T is the temperature in units of K. The results show that the Arrhenius relation is more suitable in high temperature region, while the Fulcher expression is more appropriate in undercooled region. Combining the Differential scanning calorimetry data and free-volume model, the glass forming ability of Fe_68.5Si_13.5B₉Cu₁Nb₃C₅ alloy is discussed.